Journal of Chemistry / 2021 / Article / Tab 7 / Research Article
Valorization of Glycine max (Soybean) Seed Waste: Optimization of the Microwave-Assisted Extraction (MAE) and Characterization of Polyphenols from Soybean Meal Using Response Surface Methodology (RSM) Table 7 Peak wave numbers and assignation.
Wave number (cm−1 ) Vibration Assignment Reference 3275 –C–OH (stretching) Water and polysaccharides [30 , 31 ] 2928 –C–H (stretching) Aliphatic chain: lipids [30 ] Isoflavones (daidzein and genistein) [32 ] 2146 –NH2 (stretching) Free amino acid and/or derivatives [33 ] 1579 –C=C (skeletal) Aromatic compounds and flavonoids 1393 –C–H (bending) –O–H (deformation) –C–O (deformation) Phenols [34 ] 1272 In plane = C–H Phenols, flavonoids, or aromatic compounds [35 ] 1040 Ester –C–O (stretching) Glycosidic groups [36 ] 991 Unidentified 922 –C–C (stretching) Alkane lipids, aminiacids, and proteins 510 Phenol ring (torsion) Phenols [37 ] 473 O–S–O (bending) SO−4 group [38 ] 409 In plane –C–OH (bending) Phenols [33 ]